Jason Paul "Cone" McCaslin (born September 3, 1980) is a Canadian musician. He is the bass guitarist and backing vocalist of punk rock band Sum 41 and Music Producer. He joined the band in November 1998. Sum 41 was signed by Island Records about a year after he joined. McCaslin began playing bass at the age of 14, as a member of a grunge garage band called Second Opinion. He is of half-Irish, half-Swedish descent.
He was born in North York, Toronto.
He acquired the nickname "Cone" from fellow band member Deryck Whibley in high school, because he frequently ate ice cream cones at lunch.